In 3rd Generation Partnership Project (3GPP), there has been defined a low access priority indicator (LAPI), with which it is possible to identify user equipment (UE) of a particular type as having a lower priority than that of other user equipment (see Non-patent document 1).
For example, consideration and introduction of M2M (Machine-to-Machine) architecture have been in progress in recent years. In the M2M architecture, machines connected to a mobile communication network communicate with each other and automatically conduct appropriate control of the machines without requiring human operations. In the case of UE compatible with the M2M architecture, a communication type, a frequency of communication, and communication traffic are different from those of ordinary UE such as a smartphone. Accordingly, a service provided to the M2M-compatible UE can be differentiated from that provided to other UE, by setting an LAPI to the M2M-compatible UE.
Non-patent document 1 defines a method of causing the UE, to which the LAPI is set, to select any of network nodes constituting a dedicated network, the network nodes including a mobility management entity (MME), a serving gateway (SGW), a PDN (Packet Data Network) gateway (PGW), and the like, i.e., a method of causing the UE to attach to the dedicated network. Specifically, when an LAPI is set to an RRC signal (an attachment request) transmitted from the UE, an eNodeB (eNB) transmits the attachment request from the UE to one of the network nodes constituting the dedicated network based on information on the dedicated network configured in advance.
The above-described method using the LAPI can cause the M2M-compatible UE to attach to the dedicated network provided separately from a network for ordinary UE such as a smartphone. As a consequence, even when congestion occurs due to traffic attributed to transmission and reception by the M2M-compatible UE, it is possible to eliminate adverse effects on the ordinary UE. Meanwhile, as mentioned above, in the case of the M2M-compatible UE, the communication type, the frequency of communication, and the communication traffic are different from those of the ordinary UE such as the smartphone. Accordingly, it is possible to install network nodes specialized in the M2M-compatible UE and provided with simplified functions, and thus to reduce capital expenditure.